1. Field of the Invention
This invention relates, generally, to bailers. More particularly, it relates to a bailer system that minimizes contamination of a liquid sample by oxygen or other gases present in ambient air.
2. Description of the Prior Art
The purpose of a bailer is to collect a liquid sample from a body of liquid fluid, such as a well, and to enable the collected sample to be delivered to a lab in the substantial absence of contamination of the sample by substances that were not present in the well when the sample was collected.
However, every known bailer allows air to contact the liquid sample after the bailer has been retrieved from a well. Oxygen in the air dissolves into the sample, contaminating it and causing a lab charged with determining the chemical make-up of the sample to produce inaccurate reports.
Many bailers are open-topped and are emptied into lab-bound containers by inverting the bailer. Such a decanting procedure allows oxygen contamination to occur.
Many bailers are emptied from the bottom by an emptying device known in the industry as a V.O.C. device. Such a device lifts a check valve at the bottom of a bailer from its valve seat so that the contents of the bailer are free to flow into a container that will be shipped to a lab. Like top-pouring, this decanting technique also allows atmospheric air to freely contact the liquid sample.
Recently, the present inventor developed an improved bailer designed to minimize contamination of the collected sample. Instead of emptying a bailer into a container, the bailer is capped at its opposite ends as soon as it is retrieved from the well. In this way, the bailer serves a dual function that of a bailer and as a container suitable for shipment to a lab. By capping the opposite ends of a full bailer, the interaction of the liquid sample and atmospheric air caused by transferring the bailer contents to a container by pouring or by use of a V.O.C. device is avoided.
However, an air bubble remains within the capped bailer because such bubble is trapped within the bailer at the time the bailer is capped. The bailer cap invented by the present inventor has a top wall and cylindrical sidewalls mounted about the periphery of the top wall in depending relation thereto. Internal screw threads are formed on an interior surface of the cylindrical sidewalls and such screw threads releasably engage external screw threads formed in the uppermost end of the bailer. The hollow cavity formed by the top wall and the cylindrical sidewalls therefore traps a small volume of air when the cap is placed onto the bailer. The hollow cavity is required to accommodate the handle or mounting means of the bailer, said mounting means having a rope or similar flexible lifting and lowering means tied thereto.
What is needed, then, is a bailer that substantially prevents air from coming into contact with the contents of the bailer. Such a bailer would enable a laboratory to test liquid fluid from a bailer that has not been contaminated by contact with atmospheric air.
More particularly, there exists a need for a bailer that traps no air bubbles therewithin when the bailer is capped for shipment to a lab.
However, in view of the prior art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the pertinent art how the identified need could be fulfilled.
The longstanding but heretofore unfulfilled need for an air-tight bailer is now met by a new, useful, and nonobvious invention that provides a complete system for collecting liquid fluids in the field and delivering said liquid fluids to a laboratory in an uncontaminated state.
The novel bailer system includes a top piece adapted to engage a main body of the bailer. The top piece has an open upper end of predetermined diameter. A mounting member adapted to be engaged by a rope means for lowering and lifting the bailer into and out of a body of liquid fluid is disposed in spanning relation to the open upper end of the top piece. Significantly, the mounting member does not extend above the plane of the open upper end so that it does not interfere with a novel closure means.
The novel closure means is provided for closing the open upper end when the bailer is full of liquid fluid. The closure means has a flat base that overlies the open upper end and has sidewalls depending from the flat base that are adapted to engage an external surface of the top piece. In this way, the closure means is secured to the top piece when the bailer is completely filled with liquid fluid so that no air is trapped within the bailer.
In a first embodiment, the closure means further includes a pair of guide plates formed integrally with the flat base wall that project upwardly therefrom. Each guide plate has a flat structure and is positioned on a diameter of the top wall in diametrically opposed relation to its counterpart guide plate.
A spout means in the form of a tube has a leading end adapted for penetrating the flat top wall of the closure means and a trailing end adapted for connection to a hose means that is in fluid communication with a laboratory container adapted to receive the sampled liquid fluid. Thus, liquid fluid within the bailer may flow through the spout means and through the hose means into the laboratory container when the leading end of the spout means penetrates the flat top wall and the bailer is inclined to provide a gravity feed.
A transverse plate of flat configuration is mounted transversely to a longitudinal axis of the spout means and a pair of slots is formed therein. Each slot has its outermost end in open communication with an edge of the transverse plate and is adapted to slidingly engage an associated closure means guide plate.
An opening is formed in the flat top wall of the closure means and an imperforate membrane covers the opening so that no liquid fluid may flow therethrough. The leading end of the spout means is adapted to penetrate the membrane. The user positions the spout means in the center of the membrane by slidingly interconnecting the slots of the transverse plate to the guide plates of the closure means.
In a second embodiment, the spout means, the transverse plate, and the membrane are obviated. Instead, an upstanding tubular spout is formed in the top wall of the closure means in diametrically opposed relation to an upstanding post. A flexible, elongate closure means has a first end secured to the post and a second imperforate end adapted to releaseably engage and seal the upstanding tubular spout.
When the first embodiment is used, a user manually squeezes a filled bailer so that the bailer overflows at its uppermost end. This ensures that all air bubbles have been removed from the hollow interior of the bailer. The novel closure means of the first embodiment is then secured to the uppermost end of the bailer to ensure that no air enters into the bailer when the squeezing action is terminated.
When the second embodiment is used, a user squeezes a filled bailer until the liquid fluid in the hollow interior of the bailer overflows the upstanding tube formed in the closure means. The free end of the flexible, elongate closure means is then brought into sealing relation to the tubular spout to ensure that no air can enter the bailer when the squeezing action is terminated.
An important object of this invention is to provide an air-tight bailer so that a laboratory test of oxygen content of a collected sample will not be contaminated with oxygen from the ambient environment.
A closely related object is to enable transfer of the contents of a full bailer to a laboratory container without allowing ambient air to contact the sampled liquid fluid as it is being transferred.
These and other important objects, advantages, and features of the invention will become clear as this description proceeds.
The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts that will be exemplified in the description set forth hereinafter and the scope of the invention will be indicated in the claims.